look here for firmware. [printrbot.com]
also try enabling communication with device with it unplugged from power, but plugged into usb. also are you using 12v supply. any higher voltage often requires modifications. I don't know for sure about printrbot board
also try enabling communication with device with it unplugged from power, but plugged into usb. also are you using 12v supply. any higher voltage often requires modifications. I don't know for sure about printrbot board